2019-08-20

Central question

Do petal length and width differ significantly in different types of irises?

Data

We use the iris dataset (built into R) to explore this question:

## Measurements:
names(iris)
## [1] "Sepal.Length" "Sepal.Width"  "Petal.Length" "Petal.Width" 
## [5] "Species"
## Species sampled:
levels(iris$Species)
## [1] "setosa"     "versicolor" "virginica"

Plot setup

We use the plotly package to easily generate an interactive plot that enables us to explore our central question:

p <- plot_ly(iris,
             x = ~Petal.Length, y = ~Petal.Width,
             type = 'scatter', mode = 'markers',
             color = ~Species)

Plot

Conclusions

  • There is noticeable separation between the setosa cluster and the other two iris types, in terms of petal length and width.

  • There is a small amount of overlap between the versicolor and virginica clusters.

  • It is plausible that the petal length and width differ significantly for the three types of irises, but this result has not been shown statistically.